This invention pertains to the art of training devices and more particularly to a golf swing training device. The invention is particularly applicable to a golf swing training device that permits a golfer to detect certain types of errors in his swing, and provides a positive indication of the error. If the golfer's swing is properly executed, the golfer is able to hit a golf ball with the training device, and again, obtain immediate and positive feedback. However, it will be appreciated that the invention has broader applications and may also be employed without actually hitting a golf ball, or in conjunction with other golf swing training methods, devices, and instruction.
A number of golf swing training devices are already known in the art, but this invention is particularly an improvement of commonly assigned U.S. Pat. No. 4,854,585 of Koch, et al. As shown and described in that patent, a two-way hinge is included in the golf club shaft to permit the club head, whether a wood or iron, to break from an aligned arrangement with the remainder of the shaft and indicate a fault or error in the golfer's swing. If a swing is technically proper, the hinge remains unbroken, the shaft portions aligned, and the golfer can strike a ball to instantly perceive the success in his swing.
U.S. Pat. No. 4,854,585, the disclosure of which is hereby incorporated by reference, teaches one preferred structure in which a hinge assembly includes a projection, a means for receiving the projection, and means for biasing the projection into the receiving means to tension or maintain the hinge in an unbroken state. More particularly, the U.S. Pat. No. 4,854,585 patent employs a ball as the projection which is biased outwardly from one hinge member by a coil spring. The ball is received in a recess on the other hinge portion to maintain the hinge and shaft portions in aligned fashion until a predetermined force imposed by a faulty swing overcomes the spring bias and permits the club head to break either rearwardly or forwardly. An adjustment member cooperates with the spring so that the tension on the ball member, and thus the hinge assembly, can be adjusted if so desired.
Golf swing training devices sold under the teachings of the U.S. Pat. No. 4,854,585 patent have met with substantial commercial success. Various potential areas for improvement, though, are addressed by the present application. A first area of improvement is directed to ease of adjustment of the tension of the hinge assembly, i.e., the force necessary to break the hinge from its aligned position. In the arrangement disclosed in U.S. Pat. No. 4,854,585, the grip must be removed from the upper portion of the shaft and an elongated tool inserted through the upper shaft portion to alter the biasing force as desired. It is deemed to be a complicated process to provide for adjustment of the training device, particularly for the end user who oftentimes does not have access to necessary equipment.
A second area of improvement is associated with the force necessary to break the hinge to indicate a faulty golf swing. That is, and due to the dynamics of a golf swing, it is deemed desirable to make it more difficult to break the hinge in one direction relative to the other direction. Thus, deflection of the club head forwardly during certain improper movements of the club will require a different magnitude of force than to break the club head rearwardly. In other words, certain errors in a golf swing are more easily detected than other errors in a golf swing.